[Provider Model] Add Wi-Fi toggle

- Network & internet Settings
  - Remove “Show airplane mode networks"

- Internet Settings
  - Add “Wi-Fi” switch preference
    - Show “Find and connect to Wi-Fi networks” in summary

- Screenshot:
  https://screenshot.googleplex.com/AnoXf4qDe2jPirP

Bug: 181858434
Test: manual test
atest -c NetworkDashboardFragmentTest \
         WifiSwitchPreferenceControllerTest
make RunSettingsRoboTests ROBOTEST_FILTER=NetworkProviderSettingsTest

Change-Id: Ic420ff40cfdfb3ae29ee6f754ce139cb54651bda

src/com/android/settings/network/NetworkDashboardFragment.java

@@ -146,7 +146,6 @@ public class NetworkDashboardFragment extends DashboardFragment implements
         controllers.add(privateDnsPreferenceController);
         if (Utils.isProviderModelEnabled(context)) {
             controllers.add(new NetworkProviderCallsSmsController(context, lifecycle));
-            controllers.add(new AirplaneSafeNetworksPreferenceController(context, lifecycle));
         }
         return controllers;
     }